Abstract

Molecular markers make possible the deployment of multiple rust genes in adapted elite lines. In this study we report a summary of the microsatellite tagging of a number of leaf rust, stem rust and stripe rust resistance genes from a variety of sources. Segregating Leichardt/ WAWHT2071 and Sunland/Arrino populations were used for mapping Lr13 and Lr28 where Leichardt and Sunland were the respective sources of the resistance genes. Lines C77.19/3*77W:549-163658 and Sr33 /2*Shortim//4*3/Jacup resistance lines were used as sources of Sr32 and Sr33 . F 2 and F 2:3 populations were used for microsatellite tagging of the genes. Very closely linked SSR markers were identified for Lr13 , Lr28 , Sr32 and Sr33 on chromosomes 2BS, 4AL, 2BS and 1DS, respectively. Results from field-based studies of various mapping populations for the characterization of adult plant rust (APR) resistances from a variety of sources such as Wyalkatchem, Yitpi and Frame will also be discussed. Molecular markers for a range of other rust resistance genes ( Lr9, Lr19/Sr25, Lr24/Sr24, Lr34/ Yr18 Lr46/Yr29, Lr47, Sr26 and Sr36 ) are currently being implemented for variety development and germplasm enhancement. The likely impact of these applications on wheat improvement will be discussed.